+
+ +

Source code for qns.entity.qchannel.dqchannel

+#    SimQN: a discrete-event simulator for the quantum networks
+#    Copyright (C) 2021-2022 Lutong Chen, Jian Li, Kaiping Xue
+#    University of Science and Technology of China, USTC.
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation, either version 3 of the License, or
+#    (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+from typing import List, Optional, Union
+import numpy as np
+from qns.entity.node.node import QNode
+from qns.models.delay.delay import DelayModel
+from qns.utils.rnd import get_rand
+from qns.entity.qchannel.qchannel import QuantumChannel
+
+
+def calculate_fidelity(init_fidelity: float, storage_time: float, storage_tau: float = 1.0) -> float:
+    if init_fidelity <= 0.25:
+        raise ValueError("init_fidelity must be greater than 0.25.")
+    if storage_tau <= 0.0:
+        raise ValueError("storage_tau must be positive.")
+    return float(0.25 + (float(init_fidelity) - 0.25) * np.exp(-float(storage_time) / float(storage_tau)))
+
+
+
+
+        # self.bandwidth = self.bandwidth - 1
+
+ +
+